The concept of desire is central to human experience, shaping behaviour, motivation, and well-being. While scientific inquiry into desire has traditionally concentrated on ‘natural rewards’, such as food, this project seeks to broaden the scope of desire research. By deploying established neurobiological frameworks, which have been instrumental in understanding natural rewards, we aim to advance knowledge of the brain networks underpinning sensory rewards, specifically touch and smell.
Existing literature details the neurobiology of desire for natural rewards, highlighting intricate neurochemical signalling systems. Endogenous opioids, endocannabinoids, and dopaminergic circuits within the meso-cortico-limbic reward pathway orchestrate the pleasurable experiences and adaptive behaviours vital for survival. These systems motivate individuals to seek, engage in, and repeat rewarding actions, forming the basis of desire.
Research has identified both overlapping and distinct brain networks supporting the different stages of reward processing, anticipation (‘wanting’), outcome (‘liking’), and learning., as well as various reward types. Initial studies indicate that sensory inputs such as C-tactile afferents (optimised tactile stimulation or ‘pleasant touch’) and olfactory stimulation can activate brain reward systems. However, the unique and shared profiles of these sensory rewards, in comparison to natural rewards, remain to be fully characterised, and the processing stages for touch and smell are not well understood.
Objectives
The primary objective of this project is to define the neurophysiological underpinnings of discrete stages of reward processing for sensory rewards (tactile and olfactory), in relation to previously studied natural rewards.
Methodologies
- Electroencephalographic (EEG) time-frequency analysis and source localisation
- Functional Magnetic Resonance Imaging (fMRI) for brain activity and network connectivity
- Activation Likelihood Estimation (ALE) meta-analysis of fMRI studies
- Subjective measures
References:
Berridge, K. C., & Kringelbach, M. L. (2015). Pleasure systems in the brain. Neuron, 86(3), 646-664.
Berridge, K. C., Robinson, T. E., & Aldridge, J. W. (2009). Dissecting components of reward:‘liking’,‘wanting’, and learning. Current opinion in pharmacology, 9(1), 65-73.
Liu, X., Hairston, J., Schrier, M., & Fan, J. (2011). Common and distinct networks underlying reward valence and processing stages: a meta-analysis of functional neuroimaging studies. Neuroscience & Biobehavioral Reviews, 35(5), 1219-1236.
Greco, A., Guidi, A., Bianchi, M., Lanata, A., Valenza, G., & Scilingo, E. P. (2019). Brain dynamics induced by pleasant/unpleasant tactile stimuli conveyed by different fabrics. IEEE journal of biomedical and health informatics, 23(6), 2417-2427.
Singh, H., Bauer, M., Chowanski, W., Sui, Y., Atkinson, D., Baurley, S., ... & Bianchi-Berthouze, N. (2014). The brain’s response to pleasant touch: An EEG investigation of tactile caressing. Frontiers in human neuroscience, 8, 893.
Rolls, E. T., Kringelbach, M. L., & De Araujo, I. E. (2003). Different representations of pleasant and unpleasant odours in the human brain. European Journal of Neuroscience, 18(3), 695-703.
Zou, L. Q., van Hartevelt, T. J., Kringelbach, M. L., Cheung, E. F., & Chan, R. C. (2016). The neural mechanism of hedonic processing and judgment of pleasant odors: An activation likelihood estimation meta-analysis. Neuropsychology, 30(8), 970.